LTE-Advanced Carrier Aggregation (CA) – from design to implementation and test challenges November 2014
Andjela Ilic-Savoia Keysight Technologies
Agenda Page 2
LTE-A Carrier Aggregation technology, and relevance in the 4G and beyond era • Key Features of LTE-Advanced • What is CA and why do we need it? • Bands and CA Deployment Scenarios • Definitions and UE Categories • How does CA work: Where is the impact and Protocol implications • What’s coming in Rel-11, 12 • Summary
Keysight Technologies Began Operations, Aug 1, ‘14 • Agilent announced Sept. 19, 2013, it would separate into:
• an Electronic Measurement company (now Keysight) • a Life Sciences, Diagnostics and Applied Markets company (to retain the Agilent name)
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Key LTE-Advanced Features Carrier Aggregation
Higher data rates (bps)
Enhanced MIMO
Het Nets
Higher spectral effiency (bps/Hz) Higher spectral effiency per coverage area (bps/Hz/Km2) Page 5
What is Carrier Aggregation? Page 6
•
Combining (using) multiple LTE carriers together in order to increase data throughput
•
Extends the maximum transmission bandwidth, up to 100 MHz, by aggregating up to five LTE carriers – a.k.a component carriers (CCs)
•
Initially defined in the 3GPP Release 10 standard
•
To preserve compatibility with existing devices, all aggregated carriers look exactly “like R8/R9” carriers.
•
Can be supported in Downlink only or both in Downlink and Uplink
•
Supported for FDD and TDD modes
Why Carrier Aggregation?
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• Lack of sufficient contiguous spectrum forces use of carrier aggregation to meet peak data rate targets • Motivation: • Achieve wider bandwidths (for throughput, throughput and also throughput) • Facilitate efficient use of fragmented spectrum • Efficient interference management for control channels in heterogeneous networks(cross scheduling optional)
≈
f
Why Carrier Aggregation - Industry Inflection Point Data Traffic Growth Driven By Smartphones Industry Trends LTE Technology & Smartphones, 2014 Continued growth and opportunity • 263 LTE networks in 97 countries* • 1371 LTE devices* • 918.6M Smartphone shipments** • Global shift (US 15%, China 33%; India growing 460% in 2013-’17)*
LTE-Advanced Carrier Aggregation Benefits: • Faster IP Data • Wider bandwidths • Reduced latency • Improved spectrum efficiency
*Source GSMA, Jan 2014
LTE-A Carrier Aggregation Solution: 10 or 20 MHz fragments aggregated to get 30 - 40MHz channel bandwidth 150 Mbps IP data
LTE Carrier # 1 20 MHz Bandwidth
150 Mbps IP data
LTE Carrier # 2 20 MHz Bandwidth
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Carrier Aggregation Modes Component Carrier (CC)–
up to 20 MHz BW
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f Intra -band contiguous allocation Band A
f
Intra-band non-contiguous allocation
Band A
≈ Band A
f Band B
Inter-band non-contiguous allocation
3GPP Release 10 RF & Performance Requirements Page 10
Component Carrier (CC)– up to 20 MHz BW
Maximum 2 CCs supported for both uplink & downlink, FDD & TDD
f Band A Intra -band contiguous
Not supported in Rel 10
f
Band A Intra-band non-contiguous
Maximum 2 CC supported f ONLY for FDD-downlink
≈ Band A
Inter-band allocation
Band B
Rel-10 Defined CA Bands Release 10 defines three CA bands:
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• Intra-band contiguous CA: • Band 1 (FDD) is defined as CA band CA_1 (IMT-2000 band) • Band 40 (TDD) are defined as CA_40 (2300 MHz TDD band)
• For inter-band non-contiguous CA: • R8 operating bands 1 and 5 are defined as one CA band named CA_1-5. (IMT-2000 and US Cellular 800 MHz bands)
Relaxing the constraint on Rel-10 CA • An important aspect of frequency bands when it comes to the 3GPP releases is that they are “release independent”. • This means that a band defined in a later release can be applied to an earlier release.
Rel-11 Carrier Aggregation Combinations Band
Lead company
Uplink
Downlink
Uplink
Downlink
Mode Page
CA-B3_B7
TeliaSonera
1710 - 1785
1805 - 1880
2500 - 2570
2620 - 2690
FDD
CA-B4_B17
AT&T
1710 – 1755
2110 - 2155
704 – 716
734 - 746
FDD
CA-B4_B13
Ericsson (Verizon)
1710 – 1755
2110 - 2155
777 - 787
746 - 756
FDD
CA-B4_B12
Cox Communications
1710 – 1755
2110 - 2155
698 – 716
728 - 746
FDD
CA-B20_B7
Huawei (Orange)
832 – 862
791 - 821
2500 - 2570
2620 - 2690
FDD
CA-B2_B17
AT&T
1850 – 1910
1930 - 1990
704 – 716
734 - 746
FDD
CA-B4_B5
AT&T
1710 – 1755
2110 - 2155
824 – 849
869 - 894
FDD
CA-B5_B12
US Cellular
824 – 849
869 - 894
698 – 716
728 - 746
FDD
CA-B5_B17
AT&T
824 – 849
869 - 894
704 – 716
734 - 746
FDD
CA-B20_B3
Vodafone
832 – 862
791 - 821
1710 - 1785
1805 - 1880
FDD
CA-B20_B8
Vodafone
832 – 862
791 - 821
880 – 915
925 - 960
FDD
CA-B3_B5
SK Telecom
1710 - 1785
1805 - 1880
824 – 849
869 - 894
FDD
CA-B7
China Unicom
2500 - 2570
2620 - 2690
2500 - 2570
2620 - 2690
FDD
CA-B1_B7
China Telecomm
1920 - 1980
2110 - 2170
2500 - 2570
2620 - 2690
FDD
CA-B4_B7
Rogers Wireless
1710 – 1755
2110 - 2155
2500 - 2570
2620 - 2690
FDD
CA-B25_25
Sprint
1850 - 1915
1930 - 1995
1850 - 1915
1930 - 1995
FDD
CA-B38
Huawei (CMCC)
2570 - 2620
2570 - 2620
2570 - 2620
2570 - 2620
TDD
CA-B41
Clearwire
2496 - 2690
2496 - 2690
2496 - 2690
2496 - 2690
TDD
© 2012 Agilent Technologies
Rel-11 Carrier Aggregation Combinations Continued… Page 13
Band
Lead company
Uplink
Downlink
Uplink
Downlink
Mode
CA-B1_B18
KDDI
1920 - 1980
2110 - 2170
815 - 830
860 - 894
FDD
CA-B1_B21
NTT DoCoMo
1920 - 1980
2110 - 2170
1447.9-1462.9
1495.9-1510.9
FDD
CA-B11_B18
KDDI
815 - 830
860 - 894
FDD
CA-B3_B8
KT
1710 - 1785
1805 - 1880
880 – 915
925 - 960
FDD
CA-B2_B4
TMO-US
1850 – 1910
1930 - 1990
1710 – 1755
2110 - 2155
FDD
CA-B1
KDDI
1920 - 1980
2110 - 2170
1920 - 1980
2110 - 2170
FDD
CA-B3_B3
SK Telecom
1710 - 1785
1805 - 1880
1710 - 1785
1805 - 1880
FDD
CA-B4_B4
TMO-US
1710 – 1755
2110 - 2155
1710 – 1755
2110 - 2155
FDD
…
…
1427.9–1427.9 1475.9- 1495.9
…
© 2012 Agilent Technologies
CA – How is it used? PCC (Primary Component Carrier)
• Random access procedure • Handles the RRC/NAS connection procedures • Measurement and mobility (handovers) procedures based on PCC
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Downlink
Uplink
SCC (Secondary Component Carrier)
• Activated only when in CONNECTED mode (can you guess why this req?) • Can be dynamically activated/deactivated (through MAC PDU) • PUSCH is optional (asymmetric CA, only on DL)
CA Deployment Scenarios (1 of 2) Scenario #1: • F1 and F2 cells are co-located and overlaid, providing same coverage.
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• Likely scenario when F1 and F2 are of the same band.
Scenario #2: F1
• F1 and F2 cells are co-located and overlaid, but F2 has smaller coverage • Only F1 provides sufficient coverage and F2 is used to improve throughput. • Likely scenario when F1 and F2 are of different bands
Scenario #3: • F1 and F2 cells are co-located but F2 antennas are directed to the cell boundaries of F1 so that cell edge throughput is increased. • F1 provides sufficient coverage and F2 potentially “fills the holes” • Likely scenario when F1 and F2 are of different bands
F2
CA Deployment Scenarios (2 of 2) Page 16
Scenario #4: • F1 provides macro coverage and on F2 Remote Radio Heads (RRHs) are used to improve throughput at hot spots.
• Likely scenario when F1 and F2 are of different bands.
Scenario #5: • Similar to scenario #2, but frequency selective repeaters are deployed to extend coverage for one of the frequencies.
To specify different CA combinations some new definitions are used: Page 18
•
Aggregated Transmission Bandwidth Configuration (ATBC): total number of aggregated physical resource blocks (PRB).
•
CA bandwidth class: indicates a combination of maximum ATBC and maximum number of CCs in each band. In R10 and R11 three classes are defined:
•
Class A: ATBC ≤ 100, maximum number of CC = 1
example: CA_1A_5A: BC1 and BC5, Inter-band, can do 2x up to 10MHz •
Class B: ATBC ≤ 100, maximum number of CC = 2
•
Class C: 100 < ATBC ≤ 200, maximum number of CC = 2
example: CA_1C: BC1, Intra-band cont., can do 2x up to 20MHz •
Class D, E, F: ATBC up to 500 For Future Study
UE Categories Page 19
UE Category
Data Rate DL/UL
Downlink
Uplink
LTE LTE-A
(Mbps)
Max number of layers
Max number of layers
Support for 64QAM
1
10 / 5
1
1
No
2
50 / 25
2
1
No
3
100 / 50
2
1
No
4
150 / 50
2
1
No
5
300 / 75
4
1
Yes
6
300 / 50
2 or 4
1 or 2
No
7
300 / 100
2 or 4
1 or 2
No
8
3000 / 1500
8
4
Yes
New UE Categories Combinations of Carrier Aggregation and Layers • There are multiple combinations of CA and layers that can meet the data rates for the new and existing UE categories
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• The following tables define the most cases for which performance requirements may be developed UE category
Category 6
capability [#CCs/BW(MHz)] 1 / 20MHz 2 / 10+10MHz 2 / 20+20MHz 2 / 10+20MHz
Category 7
1 / 20MHz 2 / 10+10MHz 2 / 20+20MHz 2 / 10+20MHz
Category 8
[2 / 20+20MHz]
DL layers [max #layers] 4 4 2 4 (10MHz) 2(20MHz) 4 4 2 4 (10MHz) 2(20MHz) 8?
Downlink
UE category
Category 6
Category 7
Category 8
capability [#CCs/BW(MHz)]
UL layers [max #layers]
1 / 20MHz
1
2 / 10+10MHz
1
1 / 10MHz
2
2 / 20+20MHz
1
1 / 20MHz
2
2 / 10+20MHz
2 (10MHz) 1 ( 20MHz)
[2 / 20+20MHz]
4?
Uplink
CA – where is the impact? •
MAC, PHY and RF are the most impacted layers
•
Aggregated carriers behave separately, including error correction, until demodulation is complete.
•
Data aggregation happens in MAC layer
•
Single instance of PDCP/RLC for aggregated carriers – as if only one carrier
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SCC communicated to UE in RRC Reconfiguration Page 22
Protocol implications – how to agree to establish CA During initial attach procedure, UE informs eNB of it’s capabilities in UEEUTRA-Capability information element:
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Further on rf-parameters v1020 UE reports in UE-EUTRA-Capability information element: Page 24
Protocol implications – how to agree to establish CA – SCC is enabled at MAC layer, and signaled to UE via RRC Reconfig:
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MAC implications how to Activate/deactivate SCC
C7
C6
C5
C4
C3
C2
Page 26
C1
R
Oct 1
Figure 6.1.3.8-1: Activation/Deactivation MAC control element
Carrier Aggregation Design Challenges: one example Page 27
Need to design front-end components that help reduce harmonics and other intermodulation products. Example: Band 17-4 combination Third harmonic
710 MHz
Band 17
740 MHz
2130 MHz
Band 4
Evolution of carrier aggregation Rel-12 Dual connectivity for LTE
By allowing CA between sites it is possible to provide continuous CA coverage using a low frequency macro (umbrella) cell and local capacity using a higher frequency small cell
Macro umbrella cell Small Small Small cell cell cell
The separation of the sites means that enhancements are required at the physical layer including multiple timing advances Page 28
Evolution of carrier aggregation Rel-13 Multi-RAT dual connectivity
The ultimate flexibility is achieved if CA is performed across radio access technologies (RATs) and in particular with today’s dominant small cell technology: WLAN.
Macro umbrella cell Small cell
WLAN
WLAN
This level of integration will force solutions to the issues of authentication and billing which continue to limit the potential of WLAN today. Page
29
LTE-Advanced Release 11, 12 &13 RAN stats 3GPP Releases 11, 12 and early 13 represent a huge growth in features and complexity • 58 Study items for feasibility of new work • 75 new features (excl. carrier aggregation), 51 with new performance requirements • 129 new carrier aggregation combinations with corresponding performance requirements
• 4 performance only requirements for features from earlier releases • 29 new conformance tests (expect ~180 at completion) Page
30
Release 9: Summary of Key Radio Features Page 31
• Home base station (femtocell) • MBMS – completion of MBSFN • Positioning Support (AGNSS) • Local Area Base Station (picocell) • Self Organizing Networks (SON) • Multicarrier / Multi-RAT Base Station (Multi Standard Radio) • Dual layer beamforming (TM8)
© 2012 Agilent Technologies
Rel-10: Stage 3 Frozen March 2011 Summary of Key Radio Features Page 32
• • • • • • • • •
Simultaneous PUCCH and PUSCH Clustered SC-FDMA Relaying – continued in Release 11 Enhanced Inter-cell Interference Coordination (eICIC) Minimization of Drive Test (MDT) Machine Type Communications (MTC) SON enhancements for self healing Transmit diversity, two- and four-layer spatial multiplexing Eight-layer spatial multiplexing including UE-specific RS (TM9)
© 2012 Agilent Technologies
Rel-11: Stage 3 Frozen Sept 2012 Summary of Key Radio Features
Page 33
• New carrier aggregation combinations (18) • Verification of radiated multi-antenna reception performance of UEs in LTE (MIMO OTA) • Signaling and procedure for interference avoidance for in-device coexistence • Coordinated multi-point operation for LTE (CoMP) • Further Enhanced Inter-cell Interference Coordination (FeICIC)
© 2012 Agilent Technologies
Rel-12: New Frequency Bands Page 35
Three new FDD frequency bands will be defined: • Downlink 1670 MHz–1675 MHz, uplink 1646.7 MHz–1651.7 MHz • for ITU Region 2 (US) • Downlink 461MHz–468 MHz, uplink 451–458 MHz • for Brasil • Downlink 2350–2360 MHz, uplink 2305–2315 MHz • US Wireless Communications Service (WCS) band
There is also a study item for: • Uplink 1980–2010 MHz and downlink 2170 MHz– 2200 MHz. • This is currently widely allocated for satellite communications but terrestrial use now being considered, particularly for ITU Region 3. • The potential for 110 MHz pairing with band 1 is also being considered.
© 2012 Agilent Technologies
3GPP Rel-12 Workshop June 2012 Page 36
The following proposals from the workshop were identified as most likely to be developed: • Dynamic TDD • Frequency separation between macro and small cells, using higher frequency bands in small cells (e.g., 3.5 GHz) • Inter-site carrier aggregation and macrocell-assisted small cells • Interworking with Wi-Fi • Continuous enhancements for machine-type communications, SON, MDT • Proximity services and device-to-device communications(LTE-Direct)
© 2012 Agilent Technologies
Rel-12: Stage 1 March 2013, Stage 3 2014? Current Work Items
Page 37
– The Release 12 work items that have been defined so far are: • New frequency bands • 13 new carrier aggregation scenarios • Bringing the total to 31 for Rel-11 & 12 to date • Carrier-based Het-Net ICIC for LTE • Extends existing co-channel ICIC to include network-based carrier selection • New Carrier Type for LTE • The so-called “lean” carrier – not backwards compatible with Rel-8. Less control channel overhead, can be switched on and off based on load • Further Downlink MIMO Enhancement for LTE-Advanced • Further enhancements for H(e)NB mobility • Inter H(eNB) and H(e)NB to macro © 2012 Agilent Technologies
Thank You!
Name: Andjela Ilic-Savoia E-mail:
[email protected]
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Extras…
Page 39
End-to-end IP data throughput test 3GPP 37.901 Application Layer Data ThroughputDLTesting Application Server
System Simulator
UL
Page 40
Test UE
App Layer Protocol
System Simulator
Channel emulator profiles
FTP over TCP/IP
LTE - settable parameters and power levels, closed loop CQI
LTE - static, EPA5, EVA5, EVA70, EVA200, ETU70
UDP over IP sf0
Channel emulator
sf1
sf2
sf3
sf4
sf5
sf6
sf7
PDSCH data sf8
sf9
DL - 3GPP 37.901 is defined with no PDSCH data in sub-frames 0 and 5 - For LTE CAT4 this reduces the headline rate from 150Mbps to 120Mbps (20MHz channel) - 3GPP 37.901 Application layer Throughput also excludes TCP/UDP protocol overhead and re-transmissions which reduce the measurement result further
CAT6 E2E IP Measurements on UXM Page 41
– 300Mbps achieved with 2x CCs and 20MHz bandwidth
E2E IP Throughput
Real world conditions Affecting UE Performance W-CDMA HSPA+
LTE-A CA CC#1
Page 42
LTE-A CA CC#2
LTE
Doppler
CA & MIMO
• Fading conditions • Doppler speed
Interference & AWGN
Multipath fading
Adaptive modulation & coding
• Degree of spatial diversity • Noise and interference conditions • Transmission mode used • Influence of adaptive modulation & coding
Need network and channel emulation to verify LTE/LTE-A device performance
Overcome LTE-A UE Design Test Challenges with Agilent’s New UXM
Assess design readiness with greater confidence
Page 43
1.
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2.
Receiver test complexities and challenges with 2CC CA, 4x2 MIMO and fading
3.
Quickly setup multiple test sequences that require different parameters for each sequence
1. E2E IP Throughput
2. Rx characterization
3. Test Parameter changes
Gain new insights for LTE-Advanced
Wring out designs with a broad range of integrated capabilities
Ensure realistic category 6 performance
LTE-Advanced carrier aggregation Page 44
DL: 300 Mbps
• Sustained bidirectional 300 Mbps/50 Mbps E2E IP data • Most highly integrated solution: multiple cells, carrier aggregation, 4x2 DL MIMO, integrated fading and built-in application server
Achieve design confidence • Unique receiver test Flexible channel allocation and closed-loop testing • Trusted transmitter test X-Series measurement science
UL: 50 Mbps
Cat 6 device
Be ready for 4G and beyond
Expand capabilities with most advanced platform architecture
Future-ready platform Page 45
• Designed for next advancements in antenna techniques, component carriers & data rates • Two independent 100 MHz RF transceivers • Two receiver paths per cell • Enables multiple cells, carrier aggregation, higher order MIMO, and integrated fading
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Versatile touchscreen • Next-generation ease of use, flexibility for the future
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•
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•
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•
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